Control of polymerization kinetics and rate of polymer precipitation as a means of controlling the aggregation and morphology in conductive polymers and precursors thereof

ABSTRACT

The present invention is directed to methods of fabricating electrically conducting polymers and precursors thereof in which the polymer has a controlled level of aggregation and morphology. This is done by controlling the rate of polymerization and the rate at which the polymer precipitates from solution during the polymerization reaction. An additive is added to the polymerization medium, said additive increasing or decreasing the rate at which the polymer precipitates from the reaction medium. When said additive is a second organic solvent, the polymerization reaction proceeds homogeneously for a longer period of time than does the corresponding polymerization reaction which does not include said additive. Control of the polymerization kinetics allows control of the morphology for the isolated polymer and in turn control of the properties of these polymers.

This application claims priority from Provisional Application U.S. Ser.No. 60/022,706 which was filed on Jul. 25, 1996.

CROSS REFERENCE TO RELATED APPLICATION

The teaching of U.S. application Ser. No. 09/043,622, filed on the sameday herewith entitled, "OXIDATIVE/REDUCTIVE METHODS OF DEAGGREGATION OFELECTRICALLY CONDUCTIVE POLYMERS AND PRECURSORS THEREOF AND METHODS OFFABRICATING PARTICLES THEREWITH" to M. Angelopoulos et al. isincorporated herein by reference.

The teaching of U.S. application Ser. No. 090/043,623, filed on the sameday herewith entitled, "VIBRATIONAL METHODS OF DEAGGREGATION OFELECTRICALLY CONDUCTIVE POLYMERS AND PRECURSORS THEREOF" to M.Angelopoulos et al. is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention is directed to methods of controlling thepolymerization kinetics and rate of polymer precipitation ofelectrically conducting polymers and precursors thereof. By so doing,electrically conducting polymers and precursors thereof are fabricatedwith controlled morphology and deaggregation. Such deaggregatedconducting polymers and precursors thereof exhibit better processabilityand higher electrical conductivity than do the corresponding aggregatedpolymers.

BACKGROUND OF THE INVENTION

Electrically conductive organic polymers have been of scientific andtechnological interest since the late 1970's. These relatively newmaterials exhibit the electronic and magnetic properties characteristicof metals while retaining the physical and mechanical propertiesassociated with conventional organic polymers. Herein we describeelectrically conducting polymers, for example polyparaphenylenevinylenes, polyparaphenylenes, polyanilines, polythiophenes, polyazines,polyfuranes, polypyrroles, polyselenophenes, poly-p-phenylene sulfides,polythianapthenes, polyacetylenes formed from soluble precursors,combinations thereof and blends thereof with other polymers andcopolymers of the monomers thereof.

These polymers are conjugated systems which are made electricallyconducting by doping. The non-doped or non-conducting form of thepolymer is referred to herein as the precursor to the electricallyconducting polymer. The doped or conducting form of the polymer isreferred to herein as the conducting polymer.

Conducting polymers have potential for a large number of applications insuch areas as electrostatic charge/discharge (ESC/ESD) protection,electromagnetic interference (EMI) shielding, resists, electroplating,corrosion protection of metals and ultimately metal replacements, i.e.wiring, plastic microcircuits, conducting pastes for variousinterconnection technologies (solder alternative) etc. Many of the aboveapplications especially those requiring high current capacity have notyet been realized because the conductivity of the processable conductingpolymers is not yet adequate for such applications. In order for thesematerials to be used in place of metals in more applications, it isdesirable to increase the conductivity of these materials. In addition,the processability of these polymers also requires improvement. Althoughsome of these polymers are soluble, the solubility is generally limitedand the solutions tend to be not stable over time.

The polyaniline class of conducting polymers has been shown to be one ofthe most promising and most suited conducting polymers for a broad rangeof commercial applications. The polymer has excellent environmentalstability and offers a simple, one-step synthesis. However, theconductivity of the material in its most general form (unsubstitutedpolyaniline doped with hydrochloric acid) is generally on the low end ofthe metallic regime most typically, on the order of 1 to 10 S/cm (A.G.Macdiarmid and A. J. Epstein, Faraday Discuss. Chem. Soc. 88, 317,1989). In addition, the processability of this class of polymers requireimprovement. Although polyaniline is a soluble polymer, it has beennoted that the solutions tend to be unstable with time. (E.J. OH et al,Synth. Met. 55-57, 977 (1993). Solutions of for example the polyanilinein the non-doped form tend to gel upon standing. Solutions greater than5% solids concentration tend to gel within hours limiting theapplicability of the polymer. It is desirable to devise methods ofincreasing the electrical conductivity of the doped polyanilines and toenhance the processability of these systems to allow broaderapplicability.

The conductivity (σ) is dependent on the number of carriers (n) set bythe doping level, the charge on the carriers (q) and on the mobility (μ)(both interchain and intrachain mobility) of the carriers.

    σ=nq=μ

Generally, n (the number of carriers) in these systems is maximized andthus, the conductivity is dependent on the mobility of the carriers. Toachieve higher conductivity, the mobility in these systems needs to beincreased. The mobility, in turn, depends on the morphology of thepolymer. The intrachain mobility depends on the degree of conjugationalong the chain, presence of defects, and on the chain conformation. Theinterchain mobility depends on the interchain interactions, theinterchain distance, and the degree of crystallinity. Thus, theconductivity is very dependent on the morphology of the polymer.

Recently, it has been shown that polyaniline in the non-doped form has atendency to aggregate as a result of interchain hydrogen bonding andthat this aggregation limits the solvation of the polymer (U.S.application Ser. No. 08/370,127 filed on Jan. 9, 1995 and U.S.application Ser. No. 08/370,128 filed on Jan. 9, 1995, the teachings ofwhich are incorporated herein by reference. It was found that certainadditives such as lithium chloride could be added to the polyaniline todisrupt the aggregation. As the aggregation was disrupted, the chainsbecame disentangled frown each other and the solvent was able to moreeffectively solvate the chains to adapt a more expanded chainconformation. As a result, the deaggregated polymer upon dopingexhibited higher levels of conductivity than did the polymer in theaggregated form. In addition, it was found that the deaggregatedsolutions were more stable with time than the corresponding aggregatedsolutions.

Herein novel methods of deaggregating conducting polymers and precursorsthereof are described. These are methods of controlling thepolymerization kinetics and the rate of polymer precipitation during thepolymerization reaction of these polymers. By so doing, the morphologyof these polymers can be controlled and the solubility of the polymersenhanced.

OBJECTS

It is an object of the present invention to control the level ofaggregation in electrically conducting polymers and precursors thereof.

It is an object of the present invention to control the morphology ofelectrically conducting polymers and precursors thereof.

It is an object of the present invention to deaggregate aggregatedmolecules which are precursors to the electrically conducting polymers.

It is an object of the present invention to deaggregate aggregatedmolecules which are precursors to the electrically conducting polymersso that the molecules can be more uniformly doped.

It is an object of the present invention to deaggregate aggregatedmolecules which are precursors to the electrically conducting polymersso that the molecules can exhibit high conductivity upon doping.

It is an object of the present invention to deaggregate aggregatedmolecules which are precursors to the electrically conducting polymersso that the molecules can exhibit good processability and good solutionstability.

It is an object of the present invention to deaggregate aggregatedmolecules which are precursors to the electrically conducting polymersso that the molecules can be more effectively processed into films,fibers, or any structural form.

It is an object of the present invention to deaggregate aggregatedmolecules which are precursors to the electrically conducting polymersso that the molecules can be more effectively processed into films,fibers, or any structural form having tunable morphology andmechanical/physical properties.

It is an object of the present invention to deaggregate aggregatedmolecules which are electrically conducting polymers.

It is an object of the present invention to deaggregate aggregatedmolecules which are electrically conducting polymers so that themolecules can exhibit good processability and good solution stability.

It is an object of the present invention to deaggregate aggregatedmolecules which are electrically conducting polymers so that themolecules can be more effectively processed into films, fibers, or anystructural form.

It is an object of the present invention to deaggregate aggregatedmolecules which are electrically conducting polymers so that themolecules can be more effectively processed into films, fibers, or anystructural form having tunable morphology and mechanical/physicalproperties.

It is an object of the present invention to increase the level ofaggregation in electrically conducting polymer and precursors thereof

It is an object of the present invention to increase the electricalconductivity of electrically conductive polymers.

It is another object of the present invention to increase the electricalconductivity of electrically conductive polymers by extending theelectrically conductive regions or islands of the electricallyconductive polymer.

It is another object of the present invention to further increase theelectrical conductivity of a deaggregated electrically conductivepolymer by stretch orientation.

SUMMARY OF THE INVENTION

A broad aspect of the present invention is a method for fabricatingelectrically conducting polymers and precursors to electricallyconducting polymers in which the level of aggregation and the morphologyare controlled and tunable.

A more specific aspect of a method of the present invention is thecontrol of the level of aggregation and morphology of electricallyconducting polymers and precursors thereof by controlling thepolymerization kinetics and the rate of polymer precipitation during thepolymerization reaction of these polymers.

Another more specific aspect of a method of the present invention is thecontrol of the polymerization kinetics and the rate of polymerprecipitation by controlling the amount of oxidant used in thepolymerization reaction.

Another more specific aspect of a method of the present invention is thecontrol of the polymerization kinetics and the rate of polymerprecipitation during the polymerization reaction by the addition of asolvent or additive to the reaction mixture that slows the rate at whichthe polymer precipitates from the reaction mixture.

Another more specific aspect of a method of the present inventionincludes deaggregating precursors to electrically conducting polymers orelectrically conducting polymers during the polymerization of thesematerials by controlling the polymerization kinetics and the rate ofpolymer precipitation.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects, features, and advantages of the present invention willbecome apparent from a consideration of the following detaileddescription of the invention when read in conjunction with the drawingFIGS., in which:

FIG. 1 is a general formula for a polyaniline; (a) is the precursor formof the polymer or the non-doped form of the polymer; (b) is the dopedform of the polymer or the electrically conducting form of polyaniline;(c) is the actual structure for the doped electrically conductingpolymer consisting of a polysemiquinone radical cation.

FIG. 2 depicts interchain hydrogen bonding in emeraldine base between anamine site of one chain and an imine site of a second chain.

FIG. 3 depicts gel permeation chromatographs(GPC) for polyaniline basein NMP. (a) polyaniine polymerized with 1:0.25 aniline/oxidant molarratio (b) polyaniline polymerized with 1:0.5 aniline/oxidant molarratio.

FIG. 4 depicts gel permeation chromatographs(GPC) for polyaniline basein NMP. (a) polyaniine polymerized with 1:0.75 aniline/oxidant molarratio (b) polyaniline polymerized with 1:1 aniline/oxidant molar ratio.

DETAILED DESCRIPTION

The present invention is directed to methods of controlling the level ofaggregation and the morphology of electrically conducting polymerprecursors and electrically conducting polymers. Examples of suchpolymers that can be used to practice the present invention are ofsubstituted and unsubstituted polyparaphenylenes,polyparaphenylevevinylenes, polyanilines, polyazines, polythiophenes,poly-p-phenylene sulfides, polyfuranes, polypyrroles, polyselenophenes,polyacetylenes formed from soluble precursors and combinations thereofand copolymers of monomers thereof. The general formula for thesepolymers can be found in U.S. Pat. No. 5,198,153 to Angelopoulos et al.the teaching of which is incorporated herein by reference. Polymerizableunits from which these polymers can be formed are described in U.S. Pat.No. 5,370,825 to Angelopoulos et al. the teaching of which isincorporated herein by reference. The present invention will bedescribed with reference to one type of polymer which is a substitutedor unsubstituted polyaniline or copolymers of polyaniline having generalformula shown in FIG. 1 wherein each R can be H or any organic orinorganic radical; each R can be the same or different; wherein each R¹can be H or any organic or inorganic radical, each R¹ can be the same ordifferent; x≧1; preferably x≧2 and y has a value from 0 to 1. Examplesof organic radicals are alkyl or aryl radicals. Examples of inorganicradicals are Si and Ge. This list is exemplary only and not limiting.

The precursor to the electrically conducting polymer form is shown inFIG. 1a. This is the non-doped form of the polymer or the base polymer.FIG. 1b shows polyaniline doped with a dopant. If the polyaniline baseis exposed to cationic species QA, the nitrogen atoms of the imine partof the polymer becomes substituted with the Q+cation to form anemeraldine salt as shown in FIG. 1b. Q+ can be selected from H+ andorganic or inorganic cations, for example, an alkyl group or a metal.

QA can be a protic acid where Q is hydrogen. When a protic acid HA isused to dope the polyaniline, the nitrogen atoms of the imine part ofthe polyaniline are protonated.

The emeraldine base form is greatly stabilized by resonance effects. Thecharges distribute through the nitrogen atoms and aromatic rings makingthe imine and amine nitrogens indistinguishable. The actual structure ofthe doped form is a delocalized polysemiquinone radical cation as shownin FIG. 1c.

Polyaniline can exist in a number of oxidation states. The emeraldineform of the polymer refers to the material that consists ofapproximately equal number of benzenoid units and quinoid units (y=≅0.5in FIG. 1). The emeraldine polymer can be reduced to the leucoemeraldinepolymer where y=1 in FIG. 1. The leucoemeraldine base form of thepolymer is not stable in ambient conditions. The emeraldine polymer canbe oxidized to the pernigraniline form where y=0; however, the fullyoxidized form of the polymer also tends not to be stable. In principle,other oxidation states intermediate between y=0 and y=1 are possible.The emeraldine base form of the polyaniline is the most stable form.Because of its environmental stability, it is the form of polyanilinethat has been the most abundantly studied and is the form that is suitedfor technological applications. The most preferred embodiment of thepresent invention is emeraldine base form of the polyaniline wherein yhas a value of approximately 0.5.

The emeraldine base form of polyaniline is soluble in various organicsolvents and in various aqueous acid solutions. Examples of organicsolvents are dimethylsulfoxide (DMSO), dimethylformamide (DMF),N-methylpyrrolidinone (NMP), N,N'dimethyl propylene urea (DMPU),pyridine, m-cresol, phenol. This list is exemplary only and notlimiting. Examples of aqueous acid solutions is aqueous acetic acid andformic acid solutions. This list is exemplary only and not limiting.

Previously we disclosed (U.S. Ser. No. 08/370,127 filed on Jan. 9, 1995and U.S. application Ser. No. 08/370,128 filed on Jan. 9, 1995, theteachings of which are incorporated herein by reference.) thatpolyaniline in the emeraldine base form aggregates as a result ofinterchain hydrogen bonding between the amine and imine sites as shownschematically in FIG. 2. These aggregates were evidenced by a bimodalmolecular weight distribution in gel permeation chromatography.Emeraldine base in NMP for example exhibits a bimodal distributionconsisting of high molecular weight fractions. This high molecularweight fraction is due to chain aggregation resulting in "pseudo" highmolecular weights. Previously we disclosed that certain additives suchas lithium chloride could be added to these solutions to disrupt thehydrogen bonding and in turn reduce or eliminate the high molecularweight fractions. Herein, we disclose novel methods of controlling theaggregation in polyaniline by controlling the polymerization kineticsand rate of polymer precipitation during the synthesis.

Polyaniline is synthesized by the chemical oxidation of the appropriateaniline monomer using an oxidant such as ammonium peroxydisulfate (A. G.MacDiarmid et al, in Conducting Polymers, Alcacer L., Ed., ReidelPublications, Dordrecht, Holland, 105 (1987). The reaction is done inaqueous acid solution such as hydrochloric acid. The aniline monomer isdissolved in aqueous acid and an aqueous acid solution of the oxidant isadded to the aniline monomer. The aniline/oxidant molar ratio used is 1to 0.25. Upon addition of the oxidant to the aniline monomer, themonomer is oxidized and the polymer is formed. Within minutes of theaddition of the oxidant, the polymer precipitates from the reactionmedium. The reaction is then allowed to continue for several hours.During this time, the reaction is proceeding heterogeneously as thepolymer has precipitated from the solution whereas the oxidant is stilldissolved in solution. In contradistinction, in a homogeneous reactionall reactants are in the same phase, i.e. in solution.

Authors have found that the rate at which the polymer is formed and therate at which it precipitates from solution significantly impacts themorphology of the polymer such as the aggregation. If the polymerprecipitates too soon from the reaction medium, it does not get theopportunity for the solvent to solvate the polymer to allow the chainsto disentangle from each other and to expand. As the polymerprecipitates, it basically associates predominantly with itself and lessso with the reaction medium. Whereas, if the polymer remains soluble inthe reaction medium, more solvent/polymer interactions would beprevalent. Thus, it is important to control the rate at which thepolymer forms and precipitates. One of the reasons that the polymerprecipitates from the reaction medium is that the reaction medium isaqueous acid and the formed polymer does not dissolve in this medium.

It is found that changing the amount of oxidant dramatically impacts theaggregation level in polyaniline. Polyaniline was synthesized usinganiline/oxidant molar ratios of 1:0.25, 1:0.5, 1.0.75, and 1:1 (allother polymerization conditions were kept constant for all of theseexperiments). As the oxidant level was increased, the polymer appearedto precipitate more quickly from the reaction medium. In addition, thelevel of aggregation as evidenced by the area of the high molecularweight fractions for these polymers dramatically increased. FIGS. 3 and4 depict the gel permeation chromatography for the polyaniline samplesmade with 1:0.25 (3a), 1:0.5 (3b), 1:0.75 (4a) and 1:1 (4b). As can beseen, the area of the high molecular weight fraction increases from 4%to 38% to 48% to 81% as the oxidant level increases from 1:0.25 to 1:1.A dramatic increase in the aggregation of polyaniline is observed.Authors believe that this is due to the polymer precipitating morerapidly from the reaction medium. The addition of increased oxidantchanges the kinetics of the polymerization reaction. As the oxidant isincreased, the polymer precipitates more rapidly from the reaction andbecomes more aggregated. The aniline/oxidant molar ratio can range from1:0.1 to 1:.

It is also found that the addition of a second solvent to the reactionmedium allows the polyaniline to remain in solution for a significantlylonger time. The solvent is so chosen as to partially dissolve thepolyaniline. For example, polyaniline was synthesized in aqueoushydrochloric acid with the addition of NMP. NMP was added from 0.1% To100% relative to the acid solution. Polyaniline synthesized in thisfashion did not precipitate from the reaction medium even after 1 hourof polymerization. The area of the high molecular weight fraction inthis polymer decreased. It was also observed that the actual molecularweight of the polymer increased because the extent of polymerizationincreases as the polymer and oxidant are both in solution. An exeplarylist of solvents useful to add to the polymerization reaction includes:is:

N-methyl pyrrolidinone (NMP)

dimethyl sulfoxide (DMSO)

dimethyl formamide (DMF)

pyridine

toluene

xylene

m-cresol

phenol

dimethylacetamide

tetramethylurea

N-cyclohexylpyrrolidinone

pyrrolidinone

N, N' dimethyl propylene urea (DMPU)

benzyl alcohol

cyclohexanone

ethyl lactate

propylene glycol methyl ether acetate

methylethylketone

diglyme

methylisobutylketone

tetrahydrofuran

acetonitrile

diethylmalonate

propylene glycol methyl ether

isopropanol

methanol

cellosolvealcohol

This list is exemplary only and not limiting. The amount of the solventrelative to the aqueous acid solution is from 0.1 to 100%, morepreferably from 1 to 50%, and most preferably from 2 to 30%. Anexemplary list of acids used in the polymerization reaction include,aqueous acetic acid, sulfuric acid, hydrochloric acid, oxalic acid,formic acid, toluenesulfonic acid, naphthalene sulfonic acid, camphorsulfonic acid, acrylamidopropanesulfonic acid, dodecylbenzenesulfonicacid, and so on. This list is exemplary only and not limiting.

The oxidant can be ammoniumperoxydisulfate, FeC13, hydrogen peroxide,oxygen, periodates such as sodium periodate, chromates, such aspotassium dichromate, peracids such as m-chloroperoxybenzoic acid, leadacetate and so on.

While the present invention has been described with respect to preferredembodiments, numerous modifications, changes, and improvements willoccur to those skilled in the art without departing from the spirit andscope of the invention.

EXAMPLES

General Synthesis: The unsubstituted polyaniline in the emeraldine formis synthesized by the chemical oxidative polymerization of aniline in 1Naqueous HCl using ammonium peroxydisulfate as an oxidizer. Polyanilinecan also be oxidatively polymerized electrochemically as taught by W.Huang, B. Humphrey, and A. G. MacDiarmid, J. Chem. Soc. Faraday Trans.1,82, 2385, 1986. In the chemical synthesis, the aniline monomer isadded to the aqueous hydrochloric acid and cooled to 0° C. A separateoxidant solution is prepared by dissolving the oxidant, ammoniumperoxydisulfate, in aqueous hydrochloric acid. This solution is alsocooled to 0° C. The molar ratio of aniline to the oxidant is 1:0.25. Theoxidant solution is then added to the aniline solution. Upon addition ofthe oxidant, the solution turns green and within minutes the polymerprecipitates from the reaction medium. In addition, the viscosity of themixture increases. The reaction is allowed to continue for about 1 hourat 0° C. and 2 hours at room temperature. During this time, the reactionis proceeding heterogeneously as the polymer has precipitated from themedium whereas the oxidant remains soluble in the medium and thus, thegrowing polymer and the oxidant are in different phases. After thistime, the polyaniline hydrochloride salt power is filtered and washedwith aqueous hydrochloric acid followed by water. The polymer is thenneutralized to the non-doped base form by placing the powder in aqueousammonium hydroxide for ≅12 hours. The non doped polymer is thenfiltered, washed with ammonium hydroxide, then washed with methanol anddried. The polymer at this stage is in the undoped emeraldine base formas a powder.

Substituted (either on the aromatic ring or on the nitrogen)polyanilines in the emeraldine form are synthesized in the same fashionas above but using the appropriate substituted aniline monomer in thepolymerization reaction. Copolymers are made by the oxidativepolymerization of one or more monomers. Other acids can also be used inthe polymerization reaction other than hydrochloric acid. Aqueous aceticacid, sulfuric acid, organic sulfonic acids, such as aqueoustoluenesulfonic acid, dodecylbenzenesulfonic acid, camphorsulfonic acid,and so on. The o-ethoxy substituted polyaniline was prepared byoxidative polymerization of o-ethoxy aniline in 1N hydrochloric acid asdescribed above. Copolymers having various amounts of o-ethoxy contentwere synthesized by polymerizing o-ethoxyaniline and aniline in aqueous1N hydrochloric acid. The amount of o-ethoxy content in the finalpolymer was controlled by varying the feed ratio of this monomer in theinitial polymerization reaction. Other ring substituted derivatives suchas the o-hydroxyethyl substituted polyaniline described in U.S.application Ser. No. 08/595,853 filed on Feb. 2/96 entitled,"Cross-linked electrically conductive polymers and precursors thereof"and U.S. application Ser. No. 08/594/680 filed on Feb 2, 19996 entitled,"Methods of fabricating cross-linked electrically conducting polymersand precursors thereof", the teachings of which are incorporated hereinby reference.

The substituted and unsubstituted emeraldine base powder is generallyprocessed by dissolving the powder in an organic solvent. Theunsubstituted emeraldine base was dissolved in NMP at a 5-10%concentration or DMPU. The solution can be used to spin-coat films ofthe emeraldine base polymer on silicon wafers, quartz wafers, saltplates, and so on. These films were on the order of 500 A to 1.0 μm.Thicker films (on the order of 50 to 200 μm) were made by solutioncasting techniques in which the solution was poured into an aluminum panor glass dish and placed into a vacuum oven at 60° C. for 24 hours. Thesolution can also be used to process the material into a structural partor into a fiber. The substituted emeraldine base such as the o-ethoxysubstituted emeraldine base was more soluble than the unsubstitutedemeraldine base. This polymer can be dissolved in cyclohexanone,tetrahydrofuran, ethyllactate and so on. A solution was made incyclohexanone (5% solids) and this solution was used to process films(thin and thick).

Modified Synthesis 1: The polymerization of aniline described above wascarried out with the following modification. The aniline/oxidant molarratio was increased to 1:0.5. The polymer was isolated and neutralizedas described above.

Modified Synthesis 2: The polymerization of aniline described above wascarried out with the following modification. The aniline/oxidant molarratio was increased to 1:0.75. The polymer was isolated and neutralizedas described above.

Modified Synthesis 3: The polymerization of aniline described above wascarried out with the following modification. The aniline/oxidant molarratio was increased to 1:1.0. The polymer was isolated and neutralizedas described above.

The polyanilines synthesized by the various methods described above werecharacterized by gel permeation chromatography, ultra-violet/visibleabsorption, conductivity, afm, infra-red and wide angle x-rayscattering. Gel permeation chromatography indicates that as the oxidantis increased in the synthesis, the area of the high molecular weightfractions increase indicating that the aggregation in the polymerincreases. UV/visible absorption indicate that the λmax of the excitonabsorption peak of these polymers shifts towards the blue as the oxidantin the synthesis increases. This shows that the aggregation whichincreases as the oxidant increases results in a decrease in theconjugation of the polymer. AFM also indicates that the cluster size ofthe aggregates increases as the oxidant level increases. Wide angleX-ray scattering studies indicate that as the aggregation in thesepolymers increase, the crystallinity of the polymer decreases. Thus,changing the oxidant level in the polymerization reaction which in turnchanges the polymerization kinetics and the rate of polymerprecipitation, dramatically impacts the morphology of the polymer, inparticular the level of aggregation and the degree of crystallinity.

Modified Synthesis 4: Aniline monomer was dissolved in aqueoushydrochloric acid. To this solution was added an organic solvent,N-Methylpyrrolidinone. Various synthesis were done in which the amountof N-Methylpyrrolidinone ranged from 0.1% to 100% Relative to theaqueous acid solution. The oxidant was dissolved in aqueous hydrochloricacid. Upon addition of the oxidant to the aniline solution, the solutionturned color indicating polymerization but the polymer did notprecipitate within minutes as described above. For 10% NMP and higherlevels, the polymer did not precipitate for at least one hour ofpolymerization. The polymer which was isolated from this synthesisexhibited decreased levels of aggregation.

Modified Synthesis 5: Aniline monomer was dissolved in aqueoushydrochloric acid. To this solution was added an organic solvent,Dimethylene propylene urea. Various synthesis were done in which theamount of Dimethylene propylene urea ranged from 0.1% to 100% Relativeto the aqueous acid solution. The oxidant was dissolved in aqueoushydrochloric acid. Upon addition of the oxidant to the aniline solution,the solution turned color indicating polymerization but the polymer didnot precipitate within minutes as described above. For 10% dimethylenepropylene urea, and higher levels, the polymer did not precipitate forat least one hour of polymerization. The polymer which was isolated fromthis synthesis exhibited decreased levels of aggregation.

Modified Synthesis 6: Aniline monomer was dissolved in aqueoushydrochloric acid. To this solution was added an organic solvent,Dimethylacetamice. Various synthesis were done in which the amount ofDimethylacetamide ranged from 0.1% to 100% Relative to the aqueous acidsolution. The oxidant was dissolved in aqueous hydrochloric acid. Uponaddition of the oxidant to the aniline solution, the solution turnedcolor indicating polymerization but the polymer did not precipitatewithin minutes as described above. For 10% dimethylacetamide, and higherlevels, the polymer did not precipitate for at least one hour ofpolymerization. The polymer which was isolated from this synthesisexhibited decreased levels of aggregation.

A number of other solvents were used in the synthesis of polyaniline.The general synthesis was similar to that described above.

What is claimed is:
 1. A method of fabricating polymers selected fromthe group consisting of precursors to electrically conductive polymersand electrically conductive polymers, said polymers having a level ofaggregation and a morphology, comprising:providing polymerizable units;polymerizing said units to form said polymer, said polymerizing having arate of polymerization and a kinetics of precipitation; controlling saidrate and controlling said kinetics to control said level of aggregationand said morphology of said polymer.
 2. A method according to claim 1further including an additive, wherein said rate and said kinetics arecontrolled by controlling an amount of said additive.
 3. A methodaccording to claim 2 wherein said additive is present in a molar amountfrom about 1:0.1 to about 1:1 polymerizable units to additive ratio. 4.A method according to claim 2 wherein said additive is an oxidant.
 5. Amethod according to claim 4 wherein said oxidant is present in a molaramount from about 1:0.1 to about 1:1 polymerizable units to oxidantratio.
 6. A method according to claim 4 wherein said oxidant is selectedfrom the group consisting of one or more of ammoniumperoxydisulfate,FeC13, hydrogen peroxide, oxygen, periodates, chromates, peracids andlead acetate.
 7. A method according to claim 2 further including a firstsolvent and wherein said additive is a second solvent.
 8. A methodaccording to claim 7 wherein said second solvent is selected from thegroup consisting of one or more of N-methyl pyrrolidinone (NMP) dimethylsulfoxide (DMSO) dimethyl formamide (DMF) pyridine toluene xylenem-cresol phenol dimethylacetamide tetramethylureaN-cyclohexylpyrrolidinone pyrrolidinone N, N' dimethyl propylene urea(DMPU) benzyl alcohol cyclohexanone ethyl lactate propylene glycolmethyl ether acetate methylethylketone diglyme methylisobutylketonetetrahydrofuran acetonitrile dietylmalonate gamma-butyrolactonepropylene glycol methyl ether isopropanol methanol cellosolvealcoholanisole.
 9. A method according to claim 7 wherein said second solvent ispresent in an amount from about 0.1% to about 100% of first solvent. 10.A method according to claim 2 wherein said additive is selected from thegroup consisting of one or more of a salt, an oxidant, an acid and asolvent.
 11. A method according to claim 2 wherein said additive slowssaid kinetics of precipitation.
 12. A method according to claim 1wherein said polymerizable units are selected combinations thereof. 13.A method according to claim 1 wherein said precursor is selected fromthe group consisting of substituted and unsubstitutedpolyparaphenylenes, polyparaphenylevevinylenes, polyanilines,polyazines, polythiophenes, polythianaphthenes, poly-p-phenylenesulfides, polyfuranes, polypyrroles, polyselenophenes, polyacetylenesformed from soluble precursors and combinations thereof and copolymersof monomers thereof.
 14. A method according to claim 1 wherein saidelectrically conductive polymer is selected from the group consisting ofsubstituted and unsubstituted polyparaphenylenes,polyparaphenylevevinylenes, polyanilines, polyazines, polythiophenes,polythianapthenes, poly-p-phenylene sulfides, polyfuranes, polypyrroles,polyselenophenes, polyacetylenes formed from soluble precursors andcombinations thereof and copolymers of monomers thereof.
 15. A methodaccording to claim 1 wherein said rate is controlled by creating ahomogenous reaction of all reactants which are controlled to be in thesame phase.
 16. A method according to claim 1 wherein said kinetics arecontrolled by creating a homogenous reaction of all reactants which arecontrolled to be in the same phase by the addition of said additive. 17.A method according to claim 1 wherein said level and morphology arepredetermined for a desired level of said level of aggregation and adesired morphology of said morphology.
 18. A method according to claim17 wherein said desired level and said desired morphology arepredetermined by experimental or theoretical determination to determinesaid desired level and said desired morphology.
 19. A method accordingto claim 1 wherein said polymer is a polyaniline having structuralformula: ##STR1## wherein each R can be H or any organic or inorganicradical; each R can be the same or different; wherein each R¹ can be Hor any organic or inorganic radical, each R¹ can be the same ordifferent; x≧1; x≧2;y has a value of 0 to
 1. 20. A method according toclaim 1 wherein said polymer is a polyaniline having structural formula:##STR2## wherein each R can be H or any organic or inorganic radical;each R can be the same or different; wherein each R¹ can be H or anyorganic or inorganic radical, each R¹ can be the same or different; x≧1;x≧2;y has a value of 0 to
 1. 21. A method according to claim 6 whereinsaid chromate is potassium dichromate.
 22. A method according to claim 6wherein said periodate is m-chloroperoxybenzoic acid.
 23. A methodaccording to claim 1 further including a wherein said rate at which saidpolymer is formed and said rate at which said polymer precipitates fromsolution significantly impacts said morphology of said polymer, theprecipitation of said polymer is controlled so that said polymer doesnot precipitate too soon from the reaction medium, thereby getting theopportunity for said solvent to solvate said polymer to allow chains ofsaid polymer to disentangle from each other and to expand.